From 77a837a4367a3e8ebec6c7a2736bfd4b1392b61b Mon Sep 17 00:00:00 2001
From: "Andrew Camilleri (Kukks)" <evilkukka@gmail.com>
Date: Tue, 1 Jul 2025 21:55:57 +0200
Subject: [PATCH] add bitcoin switch plugin

---
 .run/BTCPayServer_ Bitcoin-HTTPS.run.xml      |   1 +
 BTCPayServerPlugins.sln                       |  10 ++
 .../BTCPayServer.Plugins.BitcoinSwitch.csproj |  47 +++++
 .../BitcoinSwitchCOntroller.cs                |  67 +++++++
 .../BitcoinSwitchPlugin.cs                    |  23 +++
 .../BitcoinSwitchService.cs                   | 164 ++++++++++++++++++
 .../MultiValueDictionary.cs                   | 146 ++++++++++++++++
 .../MultiValueDictionaryExtensions.cs         |  18 ++
 .../README.md                                 |  17 ++
 ...witchPluginTemplateEditorItemDetail.cshtml |  12 ++
 .../_ViewImports.cshtml                       |   5 +
 11 files changed, 510 insertions(+)
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/BTCPayServer.Plugins.BitcoinSwitch.csproj
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchCOntroller.cs
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchPlugin.cs
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchService.cs
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionary.cs
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionaryExtensions.cs
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/README.md
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/Views/Shared/BitcoinSwitch/BitcoinSwitchPluginTemplateEditorItemDetail.cshtml
 create mode 100644 Plugins/BTCPayServer.Plugins.BitcoinSwitch/_ViewImports.cshtml

diff --git a/.run/BTCPayServer_ Bitcoin-HTTPS.run.xml b/.run/BTCPayServer_ Bitcoin-HTTPS.run.xml
index 8e299d0..aeefb84 100644
--- a/.run/BTCPayServer_ Bitcoin-HTTPS.run.xml	
+++ b/.run/BTCPayServer_ Bitcoin-HTTPS.run.xml	
@@ -12,6 +12,7 @@
     <option name="ADDITIONAL_IIS_EXPRESS_ARGUMENTS" value="" />
     <method v="2">
       <option name="Build Solution" enabled="true" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="ConfigBuilder" run_configuration_type="DotNetProject" />
     </method>
   </configuration>
 </component>
\ No newline at end of file
diff --git a/BTCPayServerPlugins.sln b/BTCPayServerPlugins.sln
index 67a81c8..0c7752a 100644
--- a/BTCPayServerPlugins.sln
+++ b/BTCPayServerPlugins.sln
@@ -61,6 +61,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BTCPayServer.Plugins.MicroN
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BTCPayServer.Plugins.Subscriptions", "Plugins\BTCPayServer.Plugins.Subscriptions\BTCPayServer.Plugins.Subscriptions.csproj", "{994E5D32-849B-4276-82A9-2A18DBC98D39}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BTCPayServer.Plugins.BitcoinSwitch", "Plugins\BTCPayServer.Plugins.BitcoinSwitch\BTCPayServer.Plugins.BitcoinSwitch.csproj", "{B4688F11-33F9-41AB-846E-09CE9ECF3E08}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -293,6 +295,14 @@ Global
 		{994E5D32-849B-4276-82A9-2A18DBC98D39}.Altcoins-Debug|Any CPU.Build.0 = Debug|Any CPU
 		{994E5D32-849B-4276-82A9-2A18DBC98D39}.Altcoins-Release|Any CPU.ActiveCfg = Debug|Any CPU
 		{994E5D32-849B-4276-82A9-2A18DBC98D39}.Altcoins-Release|Any CPU.Build.0 = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Altcoins-Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Altcoins-Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Altcoins-Release|Any CPU.ActiveCfg = Debug|Any CPU
+		{B4688F11-33F9-41AB-846E-09CE9ECF3E08}.Altcoins-Release|Any CPU.Build.0 = Debug|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{B19C9F52-DC47-466D-8B5C-2D202B7B003F} = {9E04ECE9-E304-4FF2-9CBC-83256E6C6962}
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BTCPayServer.Plugins.BitcoinSwitch.csproj b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BTCPayServer.Plugins.BitcoinSwitch.csproj
new file mode 100644
index 0000000..f31d0ee
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BTCPayServer.Plugins.BitcoinSwitch.csproj
@@ -0,0 +1,47 @@
+<Project Sdk="Microsoft.NET.Sdk.Razor">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <LangVersion>10</LangVersion>
+    </PropertyGroup>
+    <!-- -->
+    <!-- Plugin specific properties -->
+    <PropertyGroup>
+        <Product>Bitcoin Switch</Product>
+        <Description>Control harwdare using the POS as a switch</Description>
+        <Version>1.0.0</Version>
+        <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    </PropertyGroup>
+    <!-- Plugin development properties -->
+    <PropertyGroup>
+        <AddRazorSupportForMvc>true</AddRazorSupportForMvc>
+        <PreserveCompilationContext>false</PreserveCompilationContext>
+        <GenerateEmbeddedFilesManifest>true</GenerateEmbeddedFilesManifest>
+    </PropertyGroup>
+
+    <!-- This will make sure that referencing BTCPayServer doesn't put any artifact in the published directory -->
+    <ItemDefinitionGroup>
+        <ProjectReference>
+            <Properties>StaticWebAssetsEnabled=false</Properties>
+            <Private>false</Private>
+            <ExcludeAssets>runtime;native;build;buildTransitive;contentFiles</ExcludeAssets>
+        </ProjectReference>
+    </ItemDefinitionGroup>
+
+
+    <ItemGroup>
+        <EmbeddedResource Include="Resources\**" />
+        <ProjectReference Include="..\..\submodules\btcpayserver\BTCPayServer\BTCPayServer.csproj" />
+    </ItemGroup>
+
+
+    <ItemGroup>
+      <Folder Include="Resources\js\" />
+    </ItemGroup>
+
+
+    <ItemGroup>
+      <AdditionalFiles Include="Views\Shared\BitcoinSwitch\FileSellerTemplateEditorItemDetail.cshtml" />
+    </ItemGroup>
+
+</Project>
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchCOntroller.cs b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchCOntroller.cs
new file mode 100644
index 0000000..6d16d96
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchCOntroller.cs
@@ -0,0 +1,67 @@
+using System;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Plugins.FileSeller;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+
+namespace BTCPayServer.Plugins.BitcoinSwitch;
+
+[AllowAnonymous]
+public class BitcoinSwitchController:ControllerBase
+{
+    private readonly BitcoinSwitchService _service;
+
+    public BitcoinSwitchController(BitcoinSwitchService service)
+    {
+        _service = service;
+    }
+
+    [Route("~/apps/{id}/pos/bitcoinswitch")]
+    public async Task Connect(string id)
+    {
+        if (HttpContext.WebSockets.IsWebSocketRequest)
+        {
+            using var webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();
+           
+            await Echo(id, webSocket);
+        }
+        else
+        {
+            HttpContext.Response.StatusCode = StatusCodes.Status400BadRequest;
+        }
+    }
+    
+    private async Task Echo(string id, WebSocket webSocket)
+    {
+        try
+        {
+            _service.AppToSockets.Add(id, webSocket);
+            var buffer = new byte[1024 * 4];
+            var receiveResult = await webSocket.ReceiveAsync(
+                new ArraySegment<byte>(buffer), CancellationToken.None);
+
+            while (!receiveResult.CloseStatus.HasValue && webSocket.State == WebSocketState.Open)
+            {
+
+                receiveResult = await webSocket.ReceiveAsync(
+                    new ArraySegment<byte>(buffer), CancellationToken.None);
+            }
+
+            await webSocket.CloseAsync(
+                receiveResult.CloseStatus.Value,
+                receiveResult.CloseStatusDescription,
+                CancellationToken.None);
+
+        }
+        finally
+        {
+            _service.AppToSockets.Remove(id, webSocket);
+        }
+    }
+    
+    
+    
+}
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchPlugin.cs b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchPlugin.cs
new file mode 100644
index 0000000..82247c0
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchPlugin.cs
@@ -0,0 +1,23 @@
+using BTCPayServer.Abstractions.Contracts;
+using BTCPayServer.Abstractions.Models;
+using BTCPayServer.Plugins.FileSeller;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace BTCPayServer.Plugins.BitcoinSwitch;
+
+public class BitcoinSwitchPlugin : BaseBTCPayServerPlugin
+{
+    public override IBTCPayServerPlugin.PluginDependency[] Dependencies { get; } =
+    {
+        new() {Identifier = nameof(BTCPayServer), Condition = ">=2.0.0"}
+    };
+
+    public override void Execute(IServiceCollection applicationBuilder)
+    {
+        applicationBuilder.AddSingleton<BitcoinSwitchService>();
+        applicationBuilder.AddHostedService<BitcoinSwitchService>(provider => provider.GetRequiredService<BitcoinSwitchService>());
+        applicationBuilder.AddUIExtension("app-template-editor-item-detail", "BitcoinSwitch/BitcoinSwitchPluginTemplateEditorItemDetail");
+
+        base.Execute(applicationBuilder);
+    }
+}
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchService.cs b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchService.cs
new file mode 100644
index 0000000..c4b5c67
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/BitcoinSwitchService.cs
@@ -0,0 +1,164 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using BTCPayServer.Events;
+using BTCPayServer.HostedServices;
+using BTCPayServer.Plugins.Crowdfund;
+using BTCPayServer.Plugins.PointOfSale;
+using BTCPayServer.Services.Apps;
+using BTCPayServer.Services.Invoices;
+using BTCPayServer.Storage.Services;
+using Microsoft.Extensions.Logging;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Plugins.FileSeller
+{
+    
+    
+    
+    public class BitcoinSwitchEvent
+    {
+        public string AppId { get; set; }
+        public string Message { get; set; }
+        
+    }
+    
+    
+    public class BitcoinSwitchService : EventHostedServiceBase
+    {
+        private readonly AppService _appService;
+        private readonly InvoiceRepository _invoiceRepository;
+        public BitcoinSwitchService(EventAggregator eventAggregator,
+            ILogger<BitcoinSwitchService> logger,
+            AppService appService,
+            InvoiceRepository invoiceRepository) : base(eventAggregator, logger)
+        {
+            _appService = appService;
+            _invoiceRepository = invoiceRepository;
+        }
+
+        public ConcurrentMultiDictionary<string, WebSocket> AppToSockets { get; } = new();
+        
+
+        protected override void SubscribeToEvents()
+        {
+            Subscribe<InvoiceEvent>();
+            Subscribe<BitcoinSwitchEvent>();
+            base.SubscribeToEvents();
+        }
+
+        protected override async Task ProcessEvent(object evt, CancellationToken cancellationToken)
+        {
+            if (evt is BitcoinSwitchEvent bitcoinSwitchEvent)
+            {
+                if (AppToSockets.TryGetValues(bitcoinSwitchEvent.AppId, out var sockets))
+                {
+                    foreach (var socket in sockets)
+                    {
+                        try
+                        {
+                            await socket.SendAsync(
+                                new ArraySegment<byte>(System.Text.Encoding.UTF8.GetBytes(bitcoinSwitchEvent.Message)),
+                                WebSocketMessageType.Text, true, cancellationToken);
+                        }
+                        catch (Exception e)
+                        {
+
+                        }
+                    }
+                }
+            }
+
+            if (evt is not InvoiceEvent invoiceEvent) return;
+            List<AppCartItem> cartItems = null;
+            if (invoiceEvent.Name is not (InvoiceEvent.Completed or InvoiceEvent.MarkedCompleted
+                or InvoiceEvent.Confirmed))
+            {
+                return;
+            }
+
+            var appIds = AppService.GetAppInternalTags(invoiceEvent.Invoice);
+
+            if (!appIds.Any())
+            {
+                return;
+            }
+
+            if (invoiceEvent.Invoice.Metadata.AdditionalData.TryGetValue("bitcoinswitchactivated", out var activated))
+            {
+                return;
+            }
+
+            if ((!string.IsNullOrEmpty(invoiceEvent.Invoice.Metadata.ItemCode) ||
+                 AppService.TryParsePosCartItems(invoiceEvent.Invoice.Metadata.PosData, out cartItems)))
+            {
+                var items = cartItems ?? new List<AppCartItem>();
+                if (!string.IsNullOrEmpty(invoiceEvent.Invoice.Metadata.ItemCode) &&
+                    !items.Exists(cartItem => cartItem.Id == invoiceEvent.Invoice.Metadata.ItemCode))
+                {
+                    items.Add(new AppCartItem()
+                    {
+                        Id = invoiceEvent.Invoice.Metadata.ItemCode,
+                        Count = 1,
+                        Price = invoiceEvent.Invoice.Price
+                    });
+                }
+
+                var apps = (await _appService.GetApps(appIds)).Select(data =>
+                {
+                    switch (data.AppType)
+                    {
+                        case PointOfSaleAppType.AppType:
+                            var possettings = data.GetSettings<PointOfSaleSettings>();
+                            return (Data: data, Settings: (object) possettings,
+                                Items: AppService.Parse(possettings.Template));
+                        case CrowdfundAppType.AppType:
+                            var cfsettings = data.GetSettings<CrowdfundSettings>();
+                            return (Data: data, Settings: cfsettings,
+                                Items: AppService.Parse(cfsettings.PerksTemplate));
+                        default:
+                            return (null, null, null);
+                    }
+                }).Where(tuple => tuple.Data != null && tuple.Items.Any(item =>
+                    item.AdditionalData?.ContainsKey("bitcoinswitch_gpio") is true &&
+                    items.Exists(cartItem => cartItem.Id == item.Id)));
+
+
+                foreach (var valueTuple in apps)
+                {
+                    foreach (var item1 in valueTuple.Items.Where(item =>
+                                 item.AdditionalData?.ContainsKey("bitcoinswitch_gpio") is true &&
+                                 items.Exists(cartItem => cartItem.Id == item.Id)))
+                    {
+                        var appId = valueTuple.Data.Id;
+                        var gpio = item1.AdditionalData["bitcoinswitch_gpio"].Value<string>();
+                        var duration = item1.AdditionalData.TryGetValue("bitcoinswitch_duration", out var durationObj) &&
+                                       durationObj.Type == JTokenType.Integer
+                            ? durationObj.Value<string>()
+                            : "5000";
+
+                        PushEvent(new BitcoinSwitchEvent()
+                        {
+                            AppId = appId,
+                            Message = $"{gpio}-{duration}.0"
+                        });
+
+                    }
+                }
+
+
+                invoiceEvent.Invoice.Metadata.SetAdditionalData("bitcoinswitchactivated", "true");
+                await _invoiceRepository.UpdateInvoiceMetadata(invoiceEvent.InvoiceId, invoiceEvent.Invoice.StoreId,
+                    invoiceEvent.Invoice.Metadata.ToJObject());
+                
+                
+            }
+
+            await base.ProcessEvent(evt, cancellationToken);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionary.cs b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionary.cs
new file mode 100644
index 0000000..616df29
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionary.cs
@@ -0,0 +1,146 @@
+using System.Collections;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading;
+/// <summary>
+/// https://stackoverflow.com/a/60719233/275504
+/// </summary>
+/// <typeparam name="TKey"></typeparam>
+/// <typeparam name="TValue"></typeparam>
+public class ConcurrentMultiDictionary<TKey, TValue>
+    : IEnumerable<KeyValuePair<TKey, TValue[]>>
+{
+    private class Bag : HashSet<TValue>
+    {
+        public bool IsDiscarded { get; set; }
+    }
+
+    private readonly ConcurrentDictionary<TKey, Bag> _dictionary;
+
+    public ConcurrentMultiDictionary()
+    {
+        _dictionary = new ConcurrentDictionary<TKey, Bag>();
+    }
+
+    public int Count => _dictionary.Count;
+
+    public bool Add(TKey key, TValue value)
+    {
+        var spinWait = new SpinWait();
+        while (true)
+        {
+            var bag = _dictionary.GetOrAdd(key, _ => new Bag());
+            lock (bag)
+            {
+                if (!bag.IsDiscarded) return bag.Add(value);
+            }
+            spinWait.SpinOnce();
+        }
+    }
+    
+    public bool AddOrReplace(TKey key, TValue value)
+    {
+        Remove(key, value);
+        return Add(key, value);
+    }
+
+    public bool Remove(TKey key)
+    {
+        return _dictionary.TryRemove(key, out _);
+    }  
+    public bool Remove(TKey key, out TValue[]? items)
+    {
+        if(_dictionary.TryRemove(key, out var x))
+        {
+            items = x.ToArray();
+            return true;
+
+        }
+        items = null;
+        return false;
+    }
+    public bool Remove(TKey key, TValue value)
+    {
+        var spinWait = new SpinWait();
+        while (true)
+        {
+            if (!_dictionary.TryGetValue(key, out var bag)) return false;
+            bool spinAndRetry = false;
+            lock (bag)
+            {
+                if (bag.IsDiscarded)
+                {
+                    spinAndRetry = true;
+                }
+                else
+                {
+                    bool valueRemoved = bag.Remove(value);
+                    if (!valueRemoved) return false;
+                    if (bag.Count != 0) return true;
+                    bag.IsDiscarded = true;
+                }
+            }
+            if (spinAndRetry) { spinWait.SpinOnce(); continue; }
+            bool keyRemoved = _dictionary.TryRemove(key, out var currentBag);
+            Debug.Assert(keyRemoved, $"Key {key} was not removed");
+            Debug.Assert(bag == currentBag, $"Removed wrong bag");
+            return true;
+        }
+    }
+
+    public bool TryGetValues(TKey key, out TValue[] values)
+    {
+        if (!_dictionary.TryGetValue(key, out var bag)) { values = null; return false; }
+        bool isDiscarded;
+        lock (bag) { isDiscarded = bag.IsDiscarded; values = bag.ToArray(); }
+        if (isDiscarded) { values = null; return false; }
+        return true;
+    }
+
+    public bool Contains(TKey key, TValue value)
+    {
+        if (!_dictionary.TryGetValue(key, out var bag)) return false;
+        lock (bag) return !bag.IsDiscarded && bag.Contains(value);
+    }
+ public bool Contains(TKey key, IEnumerable<TValue> value)
+    {
+        if (!_dictionary.TryGetValue(key, out var bag)) return false;
+        lock (bag) return !bag.IsDiscarded && value.Any(bag.Contains);
+    }
+
+    public bool ContainsKey(TKey key) => _dictionary.ContainsKey(key);
+
+    public ICollection<TKey> Keys => _dictionary.Keys;
+
+    public IEnumerator<KeyValuePair<TKey, TValue[]>> GetEnumerator()
+    {
+        foreach (var key in _dictionary.Keys)
+        {
+            if (this.TryGetValues(key, out var values))
+            {
+                yield return new KeyValuePair<TKey, TValue[]>(key, values);
+            }
+        }
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    public bool ContainsValue(TValue value)
+    {
+        return _dictionary.Keys.Any(key => Contains(key, value));
+    }
+    public bool ContainsValue(IEnumerable<TValue> value)
+    {
+        return _dictionary.Keys.Any(key => Contains(key, value));
+    }
+    public IEnumerable<TKey> GetKeysContainingValue(IEnumerable<TValue> value)
+    {
+        return _dictionary.Keys.Where(key => Contains(key, value));
+    }
+    public IEnumerable<TKey> GetKeysContainingValue(TValue value)
+    {
+        return _dictionary.Keys.Where(key => Contains(key, value));
+    }
+}
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionaryExtensions.cs b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionaryExtensions.cs
new file mode 100644
index 0000000..d48da87
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/MultiValueDictionaryExtensions.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+
+namespace Relay
+{
+    public static class MultiValueDictionaryExtensions
+    {
+        public static ConcurrentMultiDictionary<TKey, TValue> ToMultiValueDictionary<TInput, TKey, TValue>(this IEnumerable<TInput> collection, Func<TInput, TKey> keySelector, Func<TInput, TValue> valueSelector)
+        {
+            var dictionary = new ConcurrentMultiDictionary<TKey, TValue>();
+            foreach (var item in collection)
+            {
+                dictionary.Add(keySelector(item), valueSelector(item));
+            }
+            return dictionary;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/README.md b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/README.md
new file mode 100644
index 0000000..5e78b44
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/README.md
@@ -0,0 +1,17 @@
+# Biotcoin Switch Plugin
+
+This plugin allows you to connect your BTCPay Server to the Bitcoin Switch hardware, developed by the amazing LNURL team.
+
+## Installation
+
+1. Go to the "Plugins" page of your BTCPay Server
+2. Click on install under the "Bitcoin Switch" plugin listing
+3. Restart BTCPay Server
+4. Go to your point of sale or crowdfund app settings
+5. Click on "Edit" on the item/perk you'd like to enable Bitcoin Switch for.
+6. Specify the hardware GPIO pin and duration of activation 
+7. Close the editor
+8. Choose Print Display in Point of Sale style (if you want to be able to print LNURL QR codes for each item specifically).
+9. Save the app
+10. Your websocket url is the point of sale url, appended with "/bitcoinswitch" and the scheme set to wss:// (e.g. wss://mybtcpay.com/apps/A9xD2nxuWzQTh33E9U6YvyyXrvA/pos/bitcoinswitch)
+11. Upon purchase (invoice marked as settled), any open websockets will receive the message to activate (io-duration)
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/Views/Shared/BitcoinSwitch/BitcoinSwitchPluginTemplateEditorItemDetail.cshtml b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/Views/Shared/BitcoinSwitch/BitcoinSwitchPluginTemplateEditorItemDetail.cshtml
new file mode 100644
index 0000000..c99e29f
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/Views/Shared/BitcoinSwitch/BitcoinSwitchPluginTemplateEditorItemDetail.cshtml
@@ -0,0 +1,12 @@
+
+<template v-if="editingItem">
+    <div class="form-group">
+        <label class="form-label">Bitcoin Switch GPIO</label>
+        <input type="number" inputmode="numeric" min="0" step="1" class="form-control mb-2" :value="editingItem['bitcoinswitch_gpio'] || ''" v-on:change="if(event.target.value) Vue.set(editingItem, 'bitcoinswitch_gpio', event.target.value); else Vue.delete(editingItem, 'bitcoinswitch_gpio');"/>
+    </div>
+    
+    <div class="form-group" v-if="editingItem['bitcoinswitch_gpio']">
+        <label class="form-label">Bitcoin Switch Duration</label>
+        <input type="number" inputmode="numeric" min="1" step="1000" class="form-control mb-2" :value="editingItem['bitcoinswitch_duration'] || ''" asp-items="files" class="form-select w-auto" v-on:change="if(event.target.value) Vue.set(editingItem, 'bitcoinswitch_duration', event.target.value); else Vue.delete(editingItem, 'bitcoinswitch_duration');"/>
+    </div>
+</template>
\ No newline at end of file
diff --git a/Plugins/BTCPayServer.Plugins.BitcoinSwitch/_ViewImports.cshtml b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/_ViewImports.cshtml
new file mode 100644
index 0000000..d897d63
--- /dev/null
+++ b/Plugins/BTCPayServer.Plugins.BitcoinSwitch/_ViewImports.cshtml
@@ -0,0 +1,5 @@
+@using BTCPayServer.Abstractions.Services
+@inject Safe Safe
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
+@addTagHelper *, BTCPayServer
+@addTagHelper *, BTCPayServer.Abstractions
\ No newline at end of file